Is Waialeale Crater actually a volcanic crater?
Should we call the above formation Waialeale Crater or the Blue Hole.
Neither! It's Olokele Canyon.
We could have inserted any of about a dozen valleys and most folks would have been unable to separate them from the Blue Hole. Even Kauai-philes wouldn't noticed the difference between Olokele or, for another instance, Waipio Valley and the so-called Waialeale Crater. So after maybe a century or so of being known as the Blue Hole did it suddenly become "Waialeale Crater." Certainly no volcanogist christened it as such.
Apparently sometime around 1990 some chopper jockey, not a geologist, decided to rename the Blue Hole. It caught on - a meme in action - just like the meme that Saddam Hussein had something to do with 9/11, a myth still believed by millions.
If you go to the Hawaii Volcano Observatory site, you'll find they call the depression atop Haleakala, Haleakala Crater (some sites use Haleakala "Crater," which would be, in my opinion, more correct) but if you read further they'll explain that it was caused by erosion. Haleakala Crater isn't a volcanic crater or caldera but a depression caused by the intersection of two erosional valleys, Kaupo and Keanae.
With the exception the offshore landslides and hydrology, there's not a great deal of geological study being done on Kauai. It's vastly overshadowed by the volcanoes on the Big Isle where at any one time, there's probably hundreds scientists of just about any discipline doing research.
Search the internet for "gological map" and Kauai or read the several books on the geology of Kauai or Hawaii, you'll find several almost identical geological maps. Most are modified from Macdonald's (and others) map which you can find on page 25 of Bulletin 13:Geology, etc., of Kauai at the Hawaii CWRM. This pdf file is the main source for info on Kauai's geology. Being an old file, it was scanned off the original so it's big(22.9 mb, 225 pages) and blurry but if you're like me and enjoy stuff like that, it's a good read.
If you take Macdonald's map or any of the others and overlay it atop a topo or DEM map of Kauai so you can get the coordinates, contours, etc.,(here's a 3-D view of Hanalei for a small inkling of what you can do if so inclined.)you can see that there are no "vents" anywhere near the Blue Hole or, as chopper pilots and guidebooks call it, Waialeale(ain't a)Crater. In fact, the Blue Hole is eroded into the Napali formation, so the rock at the bottom of the Blue Hole would be just about the most ancient of the most ancient formation on Kauai -- about five million years old.
Enough with the facts. I dare venture into opinion.
I've climbed, trekked, slept in, trod, dozens of volcano craters, calderas; active, dormant or extinct, and not one remotely resembles Waialeale(not a)Crater.
I've climbed, trekked, slept in, trod, dozens of canyons, gorges, slot canyons, (including Hawaiian), and many, especially the latter, resemble the Blue Hole.
I have dozens of chunks of recent lava, tuff, ash, etc., some still warm to the touch, and none resemble the rocks at the bottom of the Blue Hole.
If you want to touch rocks similar to those at the Blue Hole, grope a rock at Maniniholo Dry Cave on the north shore.
Sorry. There is no Waialeale (volcanic) Crater just as there is no Haleakala (volcanic) Crater. There exists not a single geological report, map, study that places a vent near what's properly called the "Blue Hole" or preferably whatever the ancient Hawaiians called it. On the contrary, when Waialeale "Volcano" stopped erupting, the surface was about four thousand feet above the Blue Hole, approximately level with the current surface at the raingage.
Does any of this matter?
Not much I confess although in my prowling of the internet I'm come across way too much idiot purple prose about flying into the ancient "fiery maw" of Waialeale. I don't live in Kauai, so if the local residents are content to the Hollywoodizing of the local names such as calling Manawaiopuna Falls Jurassic Falls because it appeared for thirty seconds in a movie as a stand in for a waterfall in Costa Rica because the producers thought the typical American was too dumb to tell the difference. Their motive I don't know since Costa Rica has plenty of waterfalls and the locals are friendlier and you could probably make it cheaper hiring Ticos.
Once upon a time there was an average tide pool, locating near a public access in Princeville. A spot where residents could find a little solitude and sun. Then some idiot decided to call it Queen's Bath. Now you gotta take a number to get a parking slot in the paved parking lot in the middle of a neighborhood and join the queue tramping up and down the cliff. Another special spot in the toilet. There's much better tide pools at .... Hell no! Find them yourselves.
Now off the soapbox. An actual Crater atop Waialeale!Simplified: Hawaii islands go through two volcanic phases, the initial formation, represented for example by the eroded Waianae mountains, Mount Waialeale, East Maui Mountains, and the later rejuvenation stage, represented by Diamond Head, Punchbowl and on Kauai, the scattered cones and surface around Koloa, the lava ridge upon which Princeville sits.
If you look west of the "M" in Mt. Waialeale on the excerpt from Macdonald's map above, you'll notice that perched atop the eastern portion of the Olokele/Alakai plateau, what's commonly called the Alakai Swamp, there's an small area of "Lavas of Koloa Volcanics series" and a vent. volcanics. I used the overlay map to derive coordinates and transferred them to a TOPO! map.
Then I zoomed in on the vent area and used the underlying -- more accurate -- NED's to place drainages and ridges around a bog I noticed from the grayscale maps.
Then I overlaid the survey photo onto a DEM.
3-D overlay looking NE
To these amateur volcanogist eyes, it appears to be a crater with a bog in the center. In size and profile, it's similar to Kilohana Crater. Let's call it Kapoki Crater (or if you don't like that, what about Mike's Crater?).
It shouldn't be surprising. It's exactly where MacDonald placed a vent, but of course this vent is not the vent that formed Mount Waialeale but a much later addition by several million years.
All this makes me wonder? Is Keaku Cave where Knudsen's used to camp back during the cowboy days, a lava tube. If so, could it harbor some insect life, like the endangered Kauai Cave Wolf Spider in the Koloa lava tubes. Are the flat areas around Sincock's and Bogs 2 & 3 caused by Koloa Lava flows.
Is every puka in Hawaii a Lava Tube?Hawaii's famous for lava tubes, but why is there a tendency to call every single hole in the ground a lava tube? Arches abound in Utah and certainly occur in Hawaii. In the Koolau and Waianae Mountains, the ridges of Waimea Canyon, if you look close, you'll find arches. So unless some geologist familiar with lava tubes who has actually put "hands on" the hole and opines that it is a lava tube, it almost certainly is an arch.
Ditto with the sea caves. Even the USGS topos of the Na Pali coast get this wrong (they are not drawn by volcanologists or geologists) although many guidebooks do get it right and call them mere sea caves. Ask yourself this, if the dozen or so "lava tubes" along the Na Pali coast formed in rock five million years ago or so, when the ocean was at a different level, the island at a much higher level, before the large chunk to the east had slide away, how did they anticipate the future sea level and all line up at sea level? Coincidence? Must be "intelligent" design!!??
And why are there not literally thousands of lava tube entrances visible on the cliffs overhead?
Why do they not extend for miles and miles inland. Kazumura Cave(a lava tube) on the Big Isle is 40 plus miles long and many other lava tubes extend miles. Ape Cave at St. Helens is two miles long. The lava tubes at Lava Beds National Momument are long. Why are the lava tubes at sea level on the Na Pali coast the same depth, more or less, as typical sea caves?
Either Kauai is home to a novel form of short, lava tube that formed at elevations anticipating a sea level five million years hence or they are sea caves.
Lava tubes are even more ephemeral than most caves. They are formed essentually on the surface and as the surface "rises" with subsequent eruptions they collapse or are filled with lava. If the surface rises thousands of feet, the few tubes that might remain will be squashed flat leaving at best a few small voids. Actually if you walk along the sea cliff at Princeville, which is atop a series of Koloa (recent) lava flows that filled the ancestral Hanalei valley, you can see some collapsed or filled lava tubes and small voids, none of which extend more than a few feet into the cliff.